Lars wrote:Neutrons should fade away within 10 - 20 minutes after the fuel is removed from the core. No problem with waiting that long. In fact, the particular application I'm thinking of would have a 4 year cool down period. So I'm thinking we are not in a high LET field.

There are some other sources of neutrons, chiefly (a,n) reactions on light elements (Li, Be, F, etc.). The alphas coming from actinide decay. Very much like a Pu238Be neutron source. Not sure if that dose rate is troublesome for electronics.

I see no reason the motors themselves should be in a high temp environment. The fuel salt needs high temp for some steps but the motor can be placed a bit away and the fuel salt insulated.

The stator would never have to be in high temp if cooling systems work. The rotor, that depends. Canned rotor type pumps are the most hermetic pumps with no need for seal gas or mechanical seals. Unfortunately they place the rotor in the product to be pumped, that means for MSRs it would have to operate hot.

The camera can be put in a container made of heavy metal. Neutrons could be dealt with by an additional layer of neutron eating material. Spare a small hole in the container for the lens and fold the optical path with mirrors in a way nuclear radiation can't follow.

It would be best to take current realities rather than 'creativity' into account when going ahead. Most of the new build is now in Asia less Japan. Asians are poised for co-operation rather than control of their actions by the big brother. Russia may be the leader in reprocessing now.

The main sticking point of the accord negotiations is whether Seoul can be allowed to use pyroprocessing technology, a reprocessing technology considered to pose fewer proliferation risks as it leaves separated plutonium mixed with other elements.

South Korea has wanted to use the technology as it can help ease the headache of the disposal of nuclear waste in a country with a small territory. But Washington has been reluctant to allow South Korea to do so due to proliferation concerns.

Under the current nuke deal, South Korea must win permission from the U.S. case by case whenever it tries to tinker with nuclear materials and technology.

Since the 1980s, Seoul has been allowed to seek overall approval from Washington every five years, but there are still lots of inconveniences and limitations for South Korea to deal with nuclear fuel under the current nuclear pact.

In 2008, the U.S. clinched a nuclear pact with the United Arab Emirates that includes explicit prohibition of uranium enrichment and reprocessing in the pact's clauses called the "Gold Standard."

Washington's recent nuke pact with Vietnam contains the Southeast Asian country's political commitment not to pursue the enrichment and reprocessing of spent fuels.

A draft of a new nuclear pact between Seoul and Washington would contain the wording of promoting "strategic cooperation" in the nuclear energy issues among the two sides, according to officials.

South Korea has been seeking to upgrade its strategic cooperation with the U.S. by taking into account its enhanced status in the nuclear power industry.

South Korea and the United States may miss the year-end target of renewing their nuclear accord as both sides remain divided over several issues, a ranking Seoul official said Wednesday.

Seoul and Washington are in the final stage of revising the 1974 accord over Seoul's civilian nuclear energy use, also known as the "123 agreement."

South Korea is hoping to win the right to enrich uranium and reprocess spent nuclear fuel to address the headache of growing nuclear waste. But the U.S. has been reluctant to do so, apparently due to possible negative impact on its global nonproliferation campaign amid concerns over North Korea's nuclear weapons program.

I feel that the situation is unfair to South Korea. They want to recycle the used fuel in a closed cycle but are held back by others.
What would be the consequences if they treat the 123 agreement as lapsed? They should be able to buy the fuel elsewhere. They can insist on the right to reprocess the fuel unless the U.S. is willing to take it back. They can have the same rights under the NPT as Japan.